I don't have a measurement on the windows, but they are probably 2.5' wide and 5' tall, and they are a single sliding window.  

It's rented, but it's in a neighborhood with no off street parking surrounded by homes that are all the same, postage stamp lots so small a kid can't throw a ball and houses so close and tall the sun doesn't reach the ground.

OR, watch a few YouTube videos  produced for self promotions and write a check and then pray t all works out!!!

Do you think a GC would want me to itemize the whole project down to the # of doorknobs and linear foot (and inches) of framing?

There was no tall concrete wall to block the noise, only the heavy vegetation naturally growing there. 

Is it 10 feet tall holding back a large hill side or a couple of feet tall where the property next to it is a few feet higher? 

I renovated the unit by replacing 32 inch doors to 36 inch and redid the bath so caregivers could nearly enter the shower area along with a wheel chair.

They put gypsum boards over real tough southern yellow pine studs, then manually put on a brown coat over an inch thick, then a thin layer of egg shell finish. 

My favorite way to build one is build a permitted $30,000 garage that is 17’ tall, close all the permits, then finish a living space out at your leisure later.

I suggest putting in at least 4 inches to cap your building and improve energy consumption, At the time of the tear off coordinate renting a blown insulation machine too and you can add insulation from the roof into the attic/crawl space above the ceiling level to avoid interior repairs.